DataInputStream readFloat() method in Java with Examples

Last Updated : 05 Jun, 2020

The readFloat() method of DataInputStream class in Java is used to read four input bytes and returns a float value. This method reads the next four bytes from the input stream and interprets it into float type and returns. Syntax:

public final float readFloat()
                  throws IOException

Specified By: This method is specified by readFloat() method of DataInput interface. Parameters: This method does not accept any parameter. Return value: This method returns the float value interpreted by the next four bytes of the input stream. Exceptions:

EOFException - It throws EOFException if the input stream is ended before four bytes can be read.
IOException - This method throws IOException if the stream is closed or some other I/O error occurs.

Below programs illustrate readFloat() method in DataInputStream class in IO package: Program 1: Assume the existence of file "demo.txt".

Java

// Java program to illustrate
// DataInputStream readFloat() method
import java.io.*;
public class GFG {
    public static void main(String[] args)
        throws IOException
    {

        // Create float array
        float[] buf = { 10, 20, 30, 40, 50 };

        // Create file output stream
        FileOutputStream outputStream
            = new FileOutputStream("c:\\demo.txt");

        // Create data output stream
        DataOutputStream dataOutputStr
            = new DataOutputStream(outputStream);

        for (float b : buf) {
            // Write float value to
            // the dataOutputStream
            dataOutputStr.writeFloat(b);
        }

        dataOutputStr.flush();

        // Create file input stream
        FileInputStream inputStream
            = new FileInputStream("c:\\demo.txt");

        // Create data input stream
        DataInputStream dataInputStr
            = new DataInputStream(inputStream);

        while (dataInputStr.available() > 0) {
            // Print float values
            System.out.println(
                dataInputStr.readFloat());
        }
    }
}

Output:

Program 2: Assume the existence of file "demo.txt".

Java

// Java program to illustrate
// DataInputStream readFloat() method
import java.io.*;
public class GFG {
    public static void main(String[] args)
        throws IOException
    {

        // Create float array
        float[] buf = { 10.9f, 20.8f,
                        30.88f, 40.76f,
                        50.678f };

        // Create file output stream
        FileOutputStream outputStream
            = new FileOutputStream("c:\\demo.txt");

        // Create data output stream
        DataOutputStream dataOutputStr
            = new DataOutputStream(outputStream);

        for (float b : buf) {
            // Write float value to
            // the dataOutputStream
            dataOutputStr.writeFloat(b);
        }

        dataOutputStr.flush();

        // Create file input stream
        FileInputStream inputStream
            = new FileInputStream("c:\\demo.txt");

        // Create data input stream
        DataInputStream dataInputStr
            = new DataInputStream(inputStream);

        while (dataInputStr.available() > 0) {
            // Print float values
            System.out.println(
                dataInputStr.readFloat());
        }
    }
}